Fluid verification system and method for infusions

ABSTRACT

An apparatus and method are provided to verify the composition of a medical fluid in a fluid container. The verification is performed at a centralized location, where light is transmitted through the fluid and detected by a sensor that generates signals representative of the spectral data of the actual composition of the fluid. These signals are compared with the spectral data of an expected composition of the fluid. Based on the comparison, a label is generated that identifies the composition of the fluid and is affixed to the fluid container. The fluid container, with the verified fluid, is distributed to the point of care.

This application is a continuation-in-part of U.S. application Ser. No.10/704,063, filed on Nov. 7, 2003, which is incorporated herein byreference in its entirety.

FIELD OF THE INVENTION

The invention is related to the verification of the contents of a fluid,and more particularly, to the analysis of a medical fluid for verifyingthe existence of a pharmaceutical drug or drugs to be infused into apatient through a fluid infusion channel.

Physicians and other medical personnel apply intravenous (“IV”) infusiontherapy to treat various medical complications in patients. IV infusiontherapy typically involves infusing medical fluids, such aspharmaceutical drugs, from a fluid source through the tubing of a fluidadministration set, and to a cannula inserted in a patient's bloodvessel.

In a typical facility, a physician enters an order for a medication fora particular patient. This order may be handled either as a simplewritten prescription slip, or it may be entered into an automatedsystem, such as a physician order entry (“POE”) system. The prescriptionis routed to the pharmacy, where the order is filled. Typically, theprescribed drug is prepared and inserted into a bag at the pharmacy. Apharmacist also identifies the contents of the bag and the patient forwhom the bag is intended, with, for example a human-readable label and abar coded label. The prepared medication is then delivered to aclinician's station for subsequent administration to the patient.

For safety reasons, and in order to achieve optimal results, thepharmaceutical drug is administered in accurate amounts as prescribed bythe doctor, and in a controlled fashion such as by using an infusionpump. An infusion pump moves fluid from the medical fluid bag through afluid infusion channel and into the patient. The infusion pump isprogrammed by a medical clinician according to the particular pumping orinfusion parameters prescribed by the doctor. The pumping parametersprogrammed into the pump by the clinician are drug and patient specific.That is, the pumping parameters are selected by the doctor based on theparticular drug prescribed and the specific patient for whom it isintended. It is the clinician's responsibility to match the prescribeddrug with the correct patient and with the properly programmed pump.

Hospitals and other institutions continually strive to provide qualitypatient care. A medical error, such as when a patient receives the wrongdrug, is a significant concern for all health care facilities. In somecases, a single patient may be prescribed simultaneous multipleinfusions, sometimes four or more, of different drugs. Typically,multiple infusions involve different infusion parameters for each drug.Further, such multiple infusions may involve multiple pump channels;e.g., one channel for each infusion; or a secondary to a primaryinfusion. Some pump systems include four or more pumping modules, eachof which comprises an infusion pump operating on a separate fluid tubingto form a separate pumping channel. Regardless of whether a system hasmultiple channels or multiple systems each having only one channel, itis important that each channel be correctly programmed to infuse theright drug into the patient. Installing the tubing from a pharmaceuticalbag into an incorrect pumping module could result in the wrong drugbeing pumped into the patient, regardless of correct drug labeling.

Prior attempts have been made to assure that the right drug isadministered to the right patient through the right channel. In oneexample, a bar code label identifying the drug and patient is applied tothe bag at the pharmacy. After a clinician manually programs the pump, abar code scanner connected to the pump is used to read the bar codelabel on the bag to verify that it identifies the same medication asthat programmed. In another example, a bar code label is applied to thebag and the label is read with a bar code scanner to automaticallyprogram the pump, thus avoiding manual programming entirely. Whiledoctors are more assured that the doses and infusion rates that theyprescribe can be delivered to the patients accurately by the pumpsavailable today, such as via the MEDLEY™ patient care system operatingthe GUARDRAILS® safety system, there remains a concern that the rightdrug is mounted to the right pump.

Even though the pump systems of today provide significant advances inthe art to avoid medication errors, there is a desire to more reliablydetermine that the correct drug is being infused. For example, thepharmacist may have made a mistake in mixing the component fluids forthe bag, or the pharmacist may have applied the wrong bar code label tothe bag. The bar code could also contain incorrect information or theclinician could scan the bar code label of the correct bag, but becomedistracted especially during emergency situations or MEDVAC (helicoptertransport for example), and connect the tube from the bag to the wrongpumping channel.

Hence, those skilled in the art recognize that a need exists to moreaccurately ensure that the correct drug or combination of drugs isproperly infused into the correct patient. More particularly, those inthe art have recognized a need to more definitely ascertain that theparticular pharmaceutical drug a pump is infusing into the patient isthe correct drug in the correct concentration.

INVENTION SUMMARY

The above stated needs and others are met by embodiments of theinvention which provide an apparatus for labeling a fluid container,comprising a source of light located and configured so as to directlight through fluid and a light sensor located so as to receive thelight that was directed through the fluid after the light has passedthrough the fluid. The light sensor provides light sensor signalsrepresentative of the spectral data of the actual composition of thefluid. A processor is provided that is adapted to compare the spectraldata of the actual composition of the fluid with spectral data of anexpected composition of the fluid. A label generator is responsive tothe processor to generate a label identifying the fluid based on thecomparison of the spectral data of the actual composition of the fluidwith the spectral data of an expected composition.

The earlier stated needs and others are also met by other embodiments ofthe invention which provide a method of controlling delivery of a fluid,comprising the steps of directing light through the fluid and sensingthe light that was directed through the fluid after the light has passedthrough the fluid. Light sensor signals representative of the spectraldata of the actual composition of the fluid are generated. The spectraldata of the actual composition of the fluid is compared with thespectral data of an expected composition of the fluid. A label isgenerated identifying the fluid based on the comparison of the spectraldata of the actual composition of the fluid with the spectral data ofthe expected composition of the fluid.

The earlier stated needs and others are also met by still furtherembodiments of the invention which provide a method of verifying a drugprior to delivery of the drug at a point of care, comprising the stepsof spectroscopically scanning a fluid, identifying a drug in the scannedfluid based on the scanning, generating a label indicating the drugbased on the identifying of the drug, and affixing the label to a fluidcontainer containing the scanned fluid.

Other features, aspects and advantages of the invention will become moreapparent from the following detailed description and the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a system in accordance with aspects of the inventionshowing a medical instrument having four medical fluid infusion pumpsconnected to respective fluid sources and a single patient throughrespective fluid administration sets. A programming module is connectedto all pumps and is shown as having a connection to a remote processorthrough a communication link. Further, a portable device is shown tocommunicate with the medical instrument through a wireless link,although a different connection is possible;

FIG. 2 is an enlarged view of the medical devices of FIG. 1 showingdisplays and control keys of the fluid infusion pumps attached to theprogramming module;

FIG. 3 is a view of one of the fluid infusion pumps of FIGS. 1 and 2with its door in the open position and the fluid infusion channel of itsrespective administration set in operative engagement with the infusionpump. Also shown at the upstream end of the pump is the optics and lighthousing for a verification system in accordance with aspects of theinvention;

FIG. 4 is a block diagram of a medical fluid verification system andmethod in accordance with aspects of the invention;

FIG. 5 is a block diagram of aspects of a system and method inaccordance with the invention where the comparison is made betweenspectral data of the contents of a fluid channel and stored spectraldata of the expected fluid composition of a channel. Also illustratedare alarm implementations and stored data bases having relevance toaspects of the invention; and

FIG. 6 is an example in perspective block view of an implementation of afluid channel through which a light beam may be transmitted to verifythe contents of the channel, the channel also having a reference portionthrough which a reference beam of light is transmitted to developspectral data concerning the composition of the wall of the channel sothat accuracy in verifying the channel contents may be improved.

FIG. 7 is a flow chart illustrating certain steps of a method inaccordance with certain embodiments of the present invention.

FIG. 8 is a schematic depiction of an apparatus constructed inaccordance with embodiments of the present invention.

FIG. 9 is a depiction of a fluid container that can be scanned accordingto certain embodiments of the present invention.

FIG. 10 is a flow chart illustrating certain steps of the method inaccordance with certain embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings in which like reference numerals refer tolike or corresponding elements among the several views, there is shownin FIG. 1, as an example, a patient care system 20 having four infusionpump modules 22, 24, 26, and 28 each of which is in operative engagementwith the tubing of a respective fluid administration set 30, 32, 34, and36. Four medical fluid sources 38, 40, 42, and 44, which may takevarious forms but in this case are shown as bottles, are inverted andsuspended above the patient care system 20. The patient care system 20and the bottles 38, 40, 42, and 44 are mounted to a roller stand or IVpole 46. The administration sets 30, 32, 34, and 36 are connectedbetween respective fluid sources and a patient 48 (shown only in blockform) so that the patient may receive the fluids in the fluid sources atrates controlled by the respective infusion pump modules. The pumpingsystem shown in FIG. 1 is provided only as an example of a system withwhich the drug verification system and method of the invention may beused. Other pumping systems and non-pumping systems, such as a gravityfeed system, may be usable in accordance with the invention.

It should be noted that the drawing of FIG. 1 is not to scale and thatdistances have been compressed for the purpose of clarity. In an actualsetting, the distance between bottles 38, 40, 42, and 44 and theinfusion pump modules 22, 24, 26, and 28 could be much greater. Therewould be more of an opportunity for the tubings of the administrationsets 30, 32, 34, and 36 to become intertwined with each other when allfour are dangling from the bottles, which can cause confusion as towhich tubing should be in which infusion module. The opportunity forconfusion increases as the number of tubings increases.

Referring now to both FIGS. 1 and 2, a programming module (“PM”) 50 isconnected to the infusion pump modules 22, 24, 26, and 28. Other devicesor modules may be attached to the PM. In one embodiment, the PM is usedto provide an interface between the infusion pump modules and externaldevices as well as to provide most of the user interface for theinfusion pump modules. The PM includes a display of 52 for visuallycommunicating various information, such as the operating parameters ofeach of the pump modules as well as displaying alert and alarm messages.The PM may also include a speaker (not shown) to provide audible alarms.The PM also has various input devices in the embodiment includingcontrol keys 54. Further details on the PM and on a patient care systemsuch as that shown in FIGS. 1 and 2 may be found in U.S. Pat. No.5,713,856 to Eggers et al., incorporated herein by reference.

The PM 50 may also include a reader 55 receiving information relating tothe infusions, such as drug identification, patient identification,nurse identification, and other information. An identification device 57is shown on a fluid container 38 which in this case is a bar code.Likewise, the reader 55 in this case is a bar code scanner. However, theidentification device may take forms such as an RFID tag, a wirelessdevice, or other, but contains an indication of the expected fluidcomposition. The indication may also include spectrum data consistentwith the expected fluid composition, or merely a drig name. Similarly,the reader may comprise an RFID reader or wireless device compatiblewith the identification device 57. The PM also has a communicationssystem with which it may communicate with a medical facility server 56or other computers and with a portable digital assistant (“PDA”) 58,such as a palm-based system, that a care giver may have so thatinformation may be transferred between such device and the PM andinfusion pump modules. Pump programming information may be uploaded intothe PM or verified from the PM. The PM may also be used to store druglibraries for use in conjunction with infusion devices as well as vitalsigns monitoring devices, and for other uses. The communications systembetween the PM and other devices may take the form of an RF (radiofrequency) system, an infrared system, a Blue Tooth system, or otherwired or wireless systems. For illustrative purposes, the communicationslink between the patient care system 20 and the medical facility server56 is shown as a solid line indicated by numeral 59. The bar codescanner and communications system may be included integrally with one ormore infusion pumps 33, 24, 26, and 28 in cases where a PM 50 is notused.

The patient care system 20 may be interconnected with various medicalfacility information systems through different means. For example, thehospital may have a main information server 56 containing patient dataand drug data. In another example, the medical facility may have variousindividual servers, such as a pharmacy server, a physician order entryserver, a patient administration server, a nurse station server, andothers. The patient care system 20 may be connected to one or more ofthese servers through various means. Hard wiring to local area networksmay be in place, but RF, IR, Blue Tooth, and other wired and wirelessconnections may be used between the patient care system and otherinformation systems of the facility. Information may also be exchangedwith the patient care system through the use of the PDA 58. In oneembodiment, the PDA may be linked to the main server 56 through wirelessor other means and can become the information conduit between thepatient and the main server.

A view of the closed front of an infusion pump module 28 is shown inFIG. 2. The pump module includes a front door 60 and a handle 62 thatoperate to lock the front door in a closed position and unlock and openthe door for access to the internal pumping and sensing mechanisms. Adisplay 64, such as an LED display, is located in plain view on the doorin this embodiment and may be used to visually communicate variousinformation relevant to the pump module, such as “alerting” and alarmmessages. Control keys 66 exist for programming and controllingoperations of the infusion pump as desired. The infusion pump module 28also includes audio alarm equipment in the form of a speaker (notshown).

Turning now to FIG. 3, the infusion pump 22 of FIGS. 1 and 2 is shown inperspective view with the front door 60 open, showing the administrationset 30 in operative engagement with the pump 22. A platen 68 is mountedbetween the door 60 and the pumping mechanism 70. In this case, thepumping mechanism is of the linear peristaltic type. Pressure sensors 72are included in the pump 22 both upstream and downstream of the pumpingmechanism. The pump also includes an air in line sensor 74 at itsdownstream end. The handle 62 includes a latch arm 76 positioned toengage a yoke 78 located on the housing 80 of the pump. Engagement ofthe yoke by the latch arm will permit the door to remain locked in theclosed position. The handle 62 also includes a sear 82 having at leastone hook 84 for use in controlling a flow stop system.

The fluid administration set 30 comprises a fluid infusion conduitextending from the fluid source 38 (FIG. 1) to the patient 48, thatincludes an upstream tube 86, a pumping segment 88, and a downstreamtube 90. Another component of the administration set tubing 30 is anupstream fitment 92 that connects the upstream tube 86 and the pumpingsegment 88. Similarly, a flow stop 94 connects the pumping segment 88and the downstream tube 90. The pumping segment 88 is mounted across thepumping mechanism 70 of the infusion pump 22 by the secure engagement ofthe upstream fitment 92 with an upper housing portion 96 and theengagement of the flow stop 94 with a lower flow stop bracket 98. Thedistance between the mounted upstream fitment and the flow stop bracketputs tension on the pumping segment 88 that, by design, tends to hold itin position over the pumping mechanism 70. When the administration set30 is engaged with the pump 22, the pumping segment is positionedagainst the pumping mechanism 70 and held in place by the platen 68which swings into operating position as the pump module door 60 isclosed.

Referring now to FIG. 4, a block diagram of a drug verification system100 in accordance with aspects of the invention is shown connected to apatient 48. A fluid source 38, which may take various forms, isconnected to the patient 48 through a fluid administration set 30, whichis referred to as a fluid delivery “channel” herein. The designation“channel” is particularly appropriate in reference to the pump systemshown in FIG. 1 because there are four lines or “channels” of drugsbeing administered to the same patient simultaneously. In the embodimentof FIG. 4, the fluid delivery channel 30 connecting the fluid source 38to the patient 48 is implemented by an infusion pump 22 that is used toprecisely control the rate of infusion of the drugs of the fluid sourceinto the patient. However, also shown is a secondary fluid supply 102that is also connected to the fluid channel 30 through a Y-site device104. It is also typical in the administration of medical fluid to apatient that a secondary infusion be conducted in which a first andsecond drug may be administered sequentially using the same infusionchannel. Such an arrangement is shown in FIG. 4 in which the secondaryfluid supply 102 is connected through a secondary fluid line 106 to thechannel 30 through the Y-site device 104. As is well known, thesecondary fluid source would be elevated above the primary fluid sourceso that only one fluid flows through the channel at once. A check valveor other device would normally be used to control the fluids in channel30 although such details well known to those skilled in the art have notbeen included so that clarity of FIG. 4 may be preserved.

In accordance with the background discussed above, it is desirable toverify the actual composition of the fluid being infused into thepatient. Such verification would be desirable regardless of the meansused to effect infusion, whether it is an infusion pump, mere gravity,or other means. An example of the use of an infusion pump is provided inthe specification and drawings herein; however, it should be recognizedthat other means may be used. Although, the embodiment described andshown herein positions the sensor of the fluid verification systemupstream of the infusion pump, verification may occur at anotherlocation or locations. For example, a sensor of fluid verificationsystem may be located downstream of the infusion pump. In the case ofgravity feed system, the fluid verification system sensor may be locatedanywhere along the fluid infusion channel. In the case of a secondaryinfusion through the same channel, it would be desirable to locate thesensor of the fluid verification system downstream of the point wherethe secondary fluid is added to the fluid channel, such as is shown inFIG. 4.

The process of verifying pharmaceuticals in an infusion pumping systemdescribed above begins with an expected drug selection and drugconcentration input to a processor 122 associate with the pumping system22 by any of the methods described, i.e., key press entry, PDA, RFID, orany other means employed by the technology in the system. The drugselection triggers the processor to access the matching drug spectraldata from a drug spectra data base 124. The processor waits for aresponse of the actual measured drug spectral data, determining if amatch or mismatch exists between the expected drug spectral patterns ofthe drug library selection and the actual drug reading from a fluidinfusion channel. Although shown as local to the pump 22 in FIG. 4, theprocessor and the data base of drug spectral data may be located otherthan proximate the pump. Further, the data base of drug spectral datamay be located remotely from the processor. For example, in the case ofthe MEDLEY™ Point-Of-Care system, the processor may be located in theprogramming module 50, FIG. 1, or even elsewhere. The data base of drugspectral data may be located at the hospital server 56 area and theprogramming module 50 will communicate directly with it. In another caseboth the processor and the data base of drug spectral data may belocated in a PDA 58. Other arrangements are possible.

Detection of fluid in channels “one” through “four” takes place withlight energy transmitted through fluids and interacting with themolecules of the fluids. The transmitted light energy at any wavelengthmay variously be attenuated, frequency shifted, or otherwise influencedby those interactions. Optical analysis means, such as dispersive,Fourier Transform Infrared (FTIR), and Raman spectroscopy, may be usedto detect the characteristics of the received optical beams. Thespectrum and related data of the fluid so obtained is used to detect thedrug or drugs of interest. The light source and other optical andelectronic components are selected to produce the required spectralresolution characteristics for differentiating drugs in the infusionchannel by comparison to a prerecorded drug library.

In one embodiment, an input beam of monochromatic or heterochromaticlight caused to impinge upon the fluid delivery channel such that intraversing the delivery channel the beam passes through the medicalfluid contained therein. After having passed through the medical fluid,the light energy, now called an output beam, is then optically analyzedas described above. The input and output beams may be conducted byoptical fibers or other suitable optical means such that the lighttransmitted through the fluid is brought to the spectrometer anddetection means contained therein. Both sides of the channel includebeam directing apparatus in this embodiment, although other arrangementsare possible. This described optical detection system is indicatedgenerally in FIG. 4 in dashed lines and is given numeral 108. Theperformance of such a detection system 108 may be improved by meansknown to those skilled in the art, such as stray light baffling, opticalfiltering, the use of confocal apertures, and heterodyne detectiontechniques.

With continuing reference to FIG. 4, a light source 110 is coupled toinput beam-forming optics 112, such as a lens and optical fiber orfibers, to provide a suitable main input beam 114 of light. The maininput beam is alternately directed by a chopper 115 to create twoseparate intermittent beams 111 and 113. One beam, i.e., the channelinput beam, is directed at the fluid channel 30 so that the light of thechannel input beam may interact with the medical fluid contents of thefluid channel. The other separate intermittent beam, i.e., the referenceinput beam 113, is directed by means of a mirror 117 through the channelmaterial only, in this case, through its “fin” 119 which is shown inmore detail in FIG. 6 and is described below. Proper direction of themain input beam may be accomplished by use of an optical fiber or fibersand a lens (not shown) forming part of the input beam-forming optics112.

Once the channel input beam 111 has interacted with the contents of thefluid channel 30, a channel output beam 116 results. Likewise, once thereference input beam 113 has interacted with the material of the channel30, a reference output beam 121 results. In this embodiment, the channeloutput beam 116 is redirected by the reflection of a second mirror 123.Both the channel output beam and the reference output beam are exposedto a chopper 125 that creates a main output beam 127. Output mainbeam-forming optics 118, such as lens (not shown) and an optical fiberor fibers, conduct the main output beam 127 to a spectrometer 120. Thereference beam output data is subtracted from the fluid spectra data.The channel output of the spectrometer is compared by a processor 122 toa drug spectra data base 124 to verify the composition of the fluidchannel. Control over the progress of the infusion may be exerted by theprocessor as a result of the verification process. In FIG. 4, it isshown that the processor 122 is connected to the infusion pump 22 thatis controlling the infusion of the medical fluid 38 to the patient 48.The medical fluid may contain a drug or drugs to be infused to thepatient. As an example, if the processor 122 were to determine that thedrug detected in the fluid channel 30 is consistent with the drugexpected to be there, the processor initiates a signal to the pump 22 tocease the infusion and provide a signal, such as an alarm.

The light source 110 may comprise an infrared (“IR”) energy source or atungsten energy source or other narrowband or broadband light.Preferably, the light source generates non destructive light that willnot alter the chemical composition of the medical fluid undergoingverification. In one embodiment, the light source is selected togenerate light that encompasses a wavelength range that interacts withthe contents of the fluid in the channel 30. In particular, the lightsource may be selected so as to produce light in a wavelength range orspectrum with which the possible contents of the fluid channel havedistinctive light absorption or reflection properties. In oneembodiment, the light source produces appropriate

IR energy in wavelength bands suitable to provide distinctive spectraldata absorption or transmittance properties in specific wavelength bandsin the IR spectrum.

In another embodiment, the light source 110 produces light of a singlewavelength that interacts with the contents of the medical fluidundergoing verification by Raman spectroscopy. In one embodiment, thelight is a monochromatic beam of visible light suitable to providedistinctive Raman spectral data for the possible fluids within thechannel 30. Upon interaction with the fluid contents of the channel, themonochromatic light undergoes excitation with a shift in electrons,known as the Raman Effect. The resulting shifts can then be analyzed toverify the chemical makeup of the fluid.

The output beam-forming optics 118 may also include a light dispersingdevice, such as a diffraction grating, that separates the output lightinto its spectrum of individual wavelengths for processing andverification. Alternatively, the light dispersing device may be aninterferometer. The distributed light impinges on a sensor that may takethe form of a photo detector array such as a CCD matrix or other lightsensitive device that generates spectral data signals representative ofthe wavelength strength of the light impinging on its individual cells.In the case of FIG. 4, the sensor is termed a spectrometer.

The spectrometer 120 communicates with the processor 122 sending thespectral data signals of the actual fluid contents of the channel 30 tothe processor for verification. The processor has many functions one ofwhich is to verify that the actual fluid contents of the channel 30,based on the received spectral data signals are the expected fluidcontents of the fluid channel 30. The processor may convert analogspectral data signals to digital data for verification. To perform theverification function, the processor matches, or attempts to match, thespectral data produced by the spectrometer with the drug spectral dataretrieved from a drug spectra data base 124. In one embodiment, theclinician has entered the identification of the expected drug contentsinto the patient case system 20 via an input device, such as the controlkeys 54 (FIG. 2) or a bar code scanner that reads a bar code labelapplied to the fluid source 38 by the pharmacist, or by means of a PDA58 (FIG. 1) or through other means, such as the RFID tag describedabove, or other device or devices. This may be done at the time thenurse loads the administration set 30 attached to the fluid source 38into pump 22.

The above identification means are examples only. Other means may beused to identify the expected composition of the fluid source, such asthe nurse selecting a drug or drug combination from a scrolling list onthe front panel of the PM 50 (FIG. 2). In this embodiment, the PM mayfirst access a drug library 126 through a processor 122 and then displayin the scrolling list only those drugs that are present in the druglibrary. This drug selection made by the nurse or by other means thenindicates to the processor what drug is expected to exist in the fluidcontents of the channel. In another embodiment, identical drug librariesmay exist in the infusion pump 22 and the processor 122. In yet anotherembodiment, a drug library may exist in the pump and is used by theprocessor 122. Additionally, the drug library 126 may also be configuredto be periodically updated though the communications system 59 using anexternal device such as a computer 56 running appropriate software orthrough the PDA 58 (FIG. 1) or by other means. Other means may be usedto indicate to the processor 122 what drug or drugs are expected in thefluid contents. For example, a main server may communicate directly withthe PM 50 or the processor 122 to indicate the identification of thedrug or drugs expected to be in the fluid channel. The above examplesare not meant to be exclusive of others and in fact, other arrangementsmay be used.

As a more general discussion, clinician-generated input prior to thecommencement of infusion triggers the initial drug data comparison andverification activities. In one embodiment, detection may continue on aperiodic basis for the remainder of the infusion.

The output from the optical detection system 108 comprises data signalsthat are transmitted to the processor 122 for analysis. The processor'smain functions are to gather and interpret:

1. user-entered drug selection spectral data patterns identified frommemory's drug library 126, selections matched to unique spectral datafrom the drug spectra data base 124;

2. diluent ratio in producing expected spectral data;

3. drug spectra as detected by the optical detection system 108 andtranslate it to a form usable with step 1 above; and

4. spectra data of the material comprising the fluid channel 30(discussed below)

Further, the processor:

5. wall material spectral data as unique from channel spectral data toisolate the spectral characteristics cause by the drugs alone (discussedbelow); and

6. attempts to match no. 5 with no. 1 above; i.e., drug spectra asidentified by user entry with the drug spectra determined by real-timemeasurement.

To re-state the above, the processor 122 compares the data obtained bythe spectroscopy of a fluid contained in the infusion channel 30 withthe stored data 124 for the drug it expects to see in the channel. Inthis embodiment, the processor may first access the drug spectra database 124, as directed by customer protocol. When the processor 122 isinformed that a drug combination should exist in the channel, analgorithm would be used to determine the appropriate spectrum. The drugspectra data base 124 may contain algorithms to permit the combinationof stored spectra for a set of drugs, compounds, and combinations ofdrugs that represent all possible compositions within the fluid channel.The drug spectra data base would include, for example, the spectraassociated with pure or compound drugs, such as sodium chloride ordopamine, and might synthesize the spectra of combinations of thesefluids. The expected composition of the fluid channel 30 is identifiedto the data processor by the user interaction, for example during pumpprogramming. The processor compares expected composition with the senseddrug obtained real-time from the channel's lumen contents. The processorcompares the expected and measured spectra and determines the degree ofcorrelation between them. Comparisons may be made on a peak-by-peakbasis, by autocorrelation, or by other means known to those skilled inthe art. The processor 122 outputs the verification results by providinga signal, indicating that either a match or no match occurred betweenthe expected and real time sensed signals.

In another embodiment, rather than having algorithms to synthesizespectra of combinations of drugs, the data base 124 may simply containspectra of all possible pure drugs and combinations of drugs, Since inone case the identification of the drug or drugs in the fluid channelinvolves a selection from a predetermined list, the choices facing thenurse or medical facility are limited. Therefore, spectra of all ofthese limited choices may be installed in the data base 124.

In another aspect, the drug spectra data base 124 may also contain lightspectrum patterns of additional agents added to a primary infusion. Suchsituations could occur where a primary infusion of dextrose is occurringand the nurse adds an additional medicine through an injection port ofthe channel downstream of the primary, but upstream of the pump, such asshown in FIG. 4. The drug spectra data base may contain spectra for eachof the possible secondary drugs and for combinations of secondary drugswith primary drugs. The data base 124 would this include spectra thatrepresents all possible compositions of the channel 30 with or withoutany possible secondary drugs.

An overview of a procedure using the system described in one embodimentcomprises:

1. The clinician identifies the expected composition of the fluid sourceto be infused;

2. The drug source 38 is mounted, the drug channel 30 primed, and thedrug channel is properly mounted in the pump 22 in the usual manner;

3. The pump is programmed for the infusion, including the identificationof the drug anticipated to be in the fluid container;

4. The pump is activated;

5. Upon activation, but prior to beginning the infusion, the input lightbeam 114 is transmitted through the fluid delivery channel, and thedetection means 108 described in this application are employed;

6. The spectra obtained from the fluid composition in the infusionchannel are compared to the stored spectra 124 of the fluid expected tobe in the infusion channel;

7. If the analysis confirms that the spectra are sufficiently similar toconclude that the fluid in the infusion channel is in-fact the druganticipated, the infusion is started. An appropriate message may appearon display to inform the user of the match; and

8. If the comparison indicates the fluid in the infusion channel doesnot sufficiently match the expected drug, an alarm or warning displayand signal may be activated. User intervention is required to begin theinfusion in this case.

The infusion pump module 22 shown in FIG. 1 may be used as the infusionpump of FIG. 4, while the PM 50 of FIG. 2 may comprise the processor122. The drug spectra data base 124 and drug library 126 may be locatedin the PM 50 as well or in other embodiments, may be located in theinfusion pump or even more remotely from the infusion pump and the PMsuch as in a nurse station or elsewhere. The communications link 59 maybe used in conjunction with a drug delivery control system in the PM 50to allow the clinical institution through a server 56, or other means,to set a drug library into memory 126 of the PM that, as an example,includes drug concentration, dose limits, and systems configurationparameters for drugs, patient weights, and hospital wards. Furtherdetails on such a drug library system can be found in U.S. Pat. No.5,681,285 to Ford, incorporated herein by reference. Other means may beused to set a drug into memory, such as a wireless connection with acommunications device, such as a PDA 58 for example (FIG. 1), or thedrug library may be loadable through different type processor, such as aportable computer as shown in U.S. Pat. No. 6,269,340 to Ford,incorporated herein by reference. Although two memories 124 and 126 areshown (FIG. 4), they may actually reside in the same physical memory.

The drug library 126 may include limits set by the clinician institutionfor each drug of the library. Such limits may take the form of maximumand minimum dosages for each drug which may be made dependent on patientfactors or other factors associated with delivery of the drug. Forexample, the dosage limits may vary depending on the weight of thepatient or body surface area (“BSA”), depending on the unit or ward ofthe medical institution in which the drug is being used (for exampleneonatal care unit (NCU), the intensive care unit (ICU), etc.), anddepending on other factors. An alarm may be provided if the nurse setsthe pump to operate outside the range between the limits for aparticular drug. In some cases, the alarm may be overridden and in othercases it may not. The medical facility may establish “soft” limits foreach drug, which may be overridden by the nurse, and “hard” limits whichmay not. In either case where a limit is exceeded, a pump 22 data log ordata log in the PM 50 or other processor in communication with theinfusion pump may record each such limit event for later analysis wherethe attempted setting is higher than the maximum or lower than theminimum dosage.

The analysis of the spectral data is shown in further detail in theblock diagram of FIG. 5. The expected composition of the fluid source isidentified to the processor 122 through an input device, such as thekeys 54 of the PM or from a remote location through a communicationslink 59 and as otherwise described above. Data of the expectedcomposition is accessed from the drug spectra data base 124 of thememory 130. The processor 122 then compares the data base drug spectrumto the drug spectrum received from the spectrometer 120 representing thefluid composition of a channel under analysis. Comparison techniquesthat may be used in matching the data have been described above andalgorithms used for comparison and matching are stored in the algorithmportion 132 of the memory 130, or elsewhere. In the event that thecomparison by the processor indicates that the spectrum of the actualfluid composition of the channel does not match the spectrum of theexpected fluid composition of the channel, the processor may provide anaudio alarm signal by means of the speaker 134, and/or a visual alarm bymeans of the screen 52 and the PM or other screen, and/or remote alarmsthrough a communication link such as 59 or other link. The memory maystore all alarm and alarm-related data 136 including any overrides 138of alarms occurring with this medical instrument. Such stored alarm andoverride data may be processed by the processor 122 or downloaded toanother system for analysis and reporting to medical care personnel.Uses of such data include determining if the drug limits in the libraryare suitable or if medical practices at the medical facility needadjustment. Other uses of the data can be made. Results of verificationmay also be stored in memory 128.

Disclosure is now provided of an example of a mechanical implementationof a channel for use with an optical detection system 108, the channelusable with the fluid verification system and method described above.Referring now to FIG. 6, an upstream fitment 158, similar to thatfitment 92 shown in FIG. 3, interconnects an upstream tube 86 and apumping segment 88 that form parts of a fluid channel 30. The fitment158 is shown having two fins 119, one of which is used with thereference input beam 113. The channel input beam 111 is shown as beingpositioned such that it extends through the approximate center of thefitment 158. After both input beams of light 111 and 113 have penetratedthe fitment and exited on the far side, in this embodiment, a channeloutput beam 116 and a reference output beam 121 result.

As shown in FIG. 3, the fitment 92 may be used to secure the fluidchannel 30 in the proper location in regard to the pump so thatsuccessful fluid verification, air-in-line sensing 74, pressure sensing72, and mechanical pumping 70 may occur. In the embodiment of FIG. 6,the fitment 158 would replace the fitment 92 in FIG. 3. FIG. 3 alsoshows a housing 160 within which may be mounted various components ofthe fluid verification system 100. In particular, although not shown inFIG. 3, components of the optical detection system 108 may be located inthe fluid verification housing 160. For example, the beam forming optics112, the first chopper 115, first mirror 117, second mirror 123, secondchopper 125 and the output beam forming optics 118 may be located in thehousing 160. Additional, or fewer, of these components may be located inthe housing depending on their implementation.

In another embodiment, the fluid verification system 100 could beconfigured to automatically compensate for the absorption and Ramanspectrum of the material of the fitting 158 without an input referencebeam 113 because the light absorption and Raman properties of thetypical plastic materials used for fluid infusion conduits are generallywell known. In this embodiment, the fluid verification system may storethe data on the conduit spectrum and automatically subtract the conduitspectrum from the fluid composition spectrum during fluid analysis.

In the case where a care giver must infuse a drug that is not in thedrug library 126, the verification system 100 may be placed in overrideand no spectral comparisons will be made, although the pump may still beoperated.

In yet another embodiment where further processing capability isavailable, the verification system 100 may first perform theabove-disclosed matching function between expected fluid composition andactual detected fluid composition. If a match does not exist, the systemwill indicate this fact to the care giver through the means discussedabove. The care giver may then have the option of requesting the systemto attempt to match the spectrum of the actual detected fluidcomposition to a spectrum or spectra in the drug spectra data base 124to identify the fluid composition. If identification is successful, theidentity of the drug may be indicated on display 52, communicatedverbally 134, or otherwise communicated to the care giver, or to others.In another aspect, the system may also be configured to permit the caregiver to directly request the system 100 to compare the spectra ofselected drugs from the drug library 126 against the spectrum of theactual detected fluid conduit composition. Through this latter means, ifidentification is successful, the care giver may then be able todetermine that the fluid administration set from one drug was mistakenlyinstalled in the infusion pump under verification and can then morequickly move the administration set to the correct pump.

In another embodiment where a system such as that shown in FIGS. 1 and 2is used in which a PM 50 controls multiple infusion pump modules 22, 24,26, and 28, and an identification of the actual drug in theadministration set is successful, the PM may simply reprogram thatinfusion module for the correct drug either automatically or at theoption of the care giver. With a system such as this, the necessarypumping program may be entered into the PM when the bag of medicament isfirst received, and the PM will properly program the specific infusionpump module with that program once the module detects the presence ofthe administration set with that particular medicament in it. Othervariations on this procedure are possible.

In the case of a secondary infusion followed or preceded by a primaryinfusion as shown in FIG. 1, it would be desirable to check thecomposition of the fluid channel downstream of the Y-site 104 multipletimes to verify both the contents of the primary fluid and the secondaryfluid being infused to the patient. In such cases the infusion channelmay contain only one or the other drug at a particular time. Thus, inaddition to verifying the contents of the infusion channel prior to thestart of the infusion, it would be a desirable feature to have thedetection means periodically monitor the contents of the fluid channel30 on an ongoing basis. Such continuous monitoring would also permit thesystem to determine when the secondary infusion is complete because thespectrum of the fluid contents of the fluid channel will change.Automating the drug verification system 100 would permit the process 122of the system to switch the pumping parameters of the infusion pump 22to those required for the primary infusion or the secondary infusion atprecisely the correct time.

In addition to the embodiments described above, certain embodiments ofthe invention provide drug identification and verification at a centralsite that may be remote from the point of care, where the drugs aredelivered to a patient. Such an embodiment provides an additional layerof protection against incorrect delivery of drugs to a patient. There isa potential that pre-formulated drugs that are purchased by adistributor, such as a pharmacy, are incorrectly marked, including thetype of drug or other parameter, such as concentration. Also, thereexists the possibility that a drug formulation at the distributor (e.g.,pharmacy) is incorrectly formulated, and not as intended. For example, amistake may have been made in the formulation that produced aconcentration of the drug that is different than intended. Or incorrectstarting materials for the drug formulation may have been mistakenlyused.

The verification system in the embodiments described with respect toFIGS. 7-10 produce a level of verification of correct drug thateliminates or mitigates the need for individual spectroscopic analysisof fluid at individual points of care. Hence, the centralizedverification system of the embodiments of FIGS. 7-10 may represent amore economical solution to a caregiver, such as a hospital, since thespectroscopic analysis is centralized and not repeated throughout thefacility. At the same time, provision is made at the point of care forverifying that the fluid in the fluid container is that fluid intendedto be delivered to the patient at the point of care. This helps toprevent a fluid that was correctly labeled at the distributor from beingdelivered (e.g., infused) to a patient that is not supposed to bereceiving that fluid.

FIG. 8 schematically depicts an apparatus for labeling a fluidcontainer, constructed in accordance with disclosed embodiments. Theapparatus includes a spectroscopic analysis system 180 and a labelgenerator 182. The spectroscopic analysis system 180 may be of generallythe same construction as that described above with respect to FIG. 1-6,or may be of another design. However, rather than performing theanalysis as fluid is pumped through a tube between a fluid source andinfusion pump at the point of care, the spectroscopic scanning andanalysis is performed at a central location, and can be done in-situthrough a fluid container. Alternatively, small samples of fluid can beremoved from their containers for scanning.

The apparatus of FIG. 8 may be in a centralized location or locations,such as a pharmacy, for example, though not limited to such example. Inoperation, the centralized location, which will be termed a“distributor” for descriptive purposes, verifies both purchased fluidsand formulated fluids.

As in the earlier-described embodiments, the embodiment of FIG. 8 may beconfigured to have increased sensitivity in fluid identification. Theenhanced sensitivity can be achieved by subtracting the spectralsignature of the fluid container in the manner described with respect tothe embodiment of FIGS. 1-6. An exemplary fluid container 184 isdepicted in FIG. 9. For purposes of scanning, the fluid container 184must have a wall 190 that allows at least some light transmission. Thespectral characteristics of the fluid container 184 may be optically orelectronically removed from the spectral analysis of the fluid 186contained in the fluid container 184 in the manner discussed earlier.The spectral characteristics of the fluid container 184 may be storedfrom previously scanned empty fluid containers. Or, a non-fluidcontaining section 188 of the fluid container 184 may be scanned toobtain the spectral characteristics of the fluid container 184. Thisallows for contemporaneous scanning of the fluid and the fluidcontainer.

The distributor may receive drug/fluid spectra compiled by themanufacturer of the product for use in the verification of the fluidspurchased from the manufacturer, or from a library compiled by themanufacturer of the spectroscopic analysis system 180. Besides verifyingpurchased fluids, the spectroscopic analysis system 180 can be used inthe formulation of fluids. When a distributor, or other user, formulatesnew mixtures, the spectra can be added to the drug library by scanninginitial batches of these mixtures using the spectroscopic analysissystem 180 itself. Thus, the new mixtures of the formulations arecompared to initial mixtures of the formulations. In this way,subsequent mixtures can be checked against a created standard.

After the spectroscopic analysis, and based on this analysis, a label isgenerated by a label generator 182 coupled to the spectroscopic analysissystem 180. The label can be a machine-readable label, and include a barcode or RFID, or other indicia that can be read by a machine. The labelcan include information identifying the fluid, based on the comparisonof the spectral data of the actual composition of the fluid with thespectral data of the expected composition of the fluid. The label caninclude other types of information, including the concentration of thefluid, and other information useful in the drug delivery process.

FIG. 7 depicts a method for controlling delivery of a fluid inaccordance with disclosed embodiments. Only certain steps are shown inFIG. 7, for illustrative purposes, with other steps being omitted orincluded within the illustrated steps. In step 210, a drug is formulatedby the distributor. Alternatively, a pre-formulated drug is received atstep 212 by the distributor. The distributor performs a spectral scan ofthe fluid in step 214, whether the drug is formulated by the distributorin step 210 or is a pre-formulated drug received in step 212. The scancan be in-situ in the fluid container, or of a sample removed from thefluid container. The spectral data of the actual composition of thefluid is compared with the expected composition of the fluid. If thecompositions are inconsistent, an indication is made to the operator forappropriate action, such as discarding the scanned fluid, re-formulatingthe fluid, notifying the drug manufacturer, etc. When the compositionsare consistent, the label generator 182 generates a label in step 216with the appropriate information, such as identifying information, andother useful information. The label is then affixed to the fluidcontainer in step 218.

After a fluid has been identified, a label generated and affixed to thefluid container, the fluid can be provided to the point of care throughdelivery channels, whether that is entirely internal within a hospital,for instance, or with external distribution. FIG. 10 depicts anexemplary process that occurs at the point of care employing theverification apparatus and procedure discussed above. The fluidcontainer 184, with the affixed label that verifies the contents of thecontainer 184, is received at the point of care in step 220. The labelof the fluid container is scanned in step 222 at the point of care by anappropriate label reading device. For example, if the information on thelabel is encoded in a bar code, the label reading device includes a barcode reader. This helps to eliminate human error in reading a label.

In step 224, an infusion device, or other drug delivery device, isprogrammed using a drug library or other means. A comparison of thescanned data from the label and of the programmed data is made in step226 by an appropriate processing device, such as a processor. Adetermination is made in step 228, based on this comparison, whether thedrug (fluid) in the container is consistent with the expected drugprogrammed into the drug delivery device. If consistent, infusion of thedrug is allowed to proceed in step 230. An infusion pumping device maybe used to perform the infusion of the drug (fluid) into the patient.

If the results of the comparison indicate that the scanned data from thelabel is inconsistent with the input identification of the expectedfluid, the fluid pumping device, such as the infusion pump, iscontrolled to prevent delivery of the fluid to the patient in step 232.An indication is made in step 232 that the label is inconsistent withthe input identification of the expected fluid. The indication may be analarm, for example. Hence, by using the verification apparatus of thepresent invention, in which the fluid is verified at a central location,delivery of an incorrect drug at the point of care is prevented. Theprevention initially occurs at the centralized location, where a labelis generated after the drug is verified so that a care giver can beconfident that the labeled fluid container will contain the correctdrug. Further prevention occurs at the point of care where the verifieddrug, as identified by the affixed label, is compared to an expecteddrug, with infusion occurring only if the verified drug is consistentwith the expected drug.

The disclosed embodiments provide a cost-effective verification systemthat employs a centralized fluid verification and fluid containerlabeling apparatus that aids in the prevention of incorrect drugdelivery at the point of care. The use of a centralized verification andlabeling apparatus mitigates certain concerns regarding incorrect drugsbeing infused into a patient, while not requiring a separate spectralanalysis system at each point of care.

Although specific embodiments of the invention have been described andillustrated it is clear that the invention is susceptible tomodifications and embodiments within the ability of those skilled in theart, and without the exercise of the inventive faculty. Thus, it shouldbe understood that various changes in form, detail, and application ofthe present invention may be made without departing from the spirit andscope of the invention.

1. An apparatus for labeling a fluid container, comprising: a source oflight located and configured so as to direct light through fluid; alight sensor located so as to receive the light that was directedthrough the fluid after the light has passed through the fluid, thelight sensor providing light sensor signals representative of thespectral data of the actual composition of the fluid; a processor thatis adapted to compare the spectral data of the actual composition of thefluid with spectral data of an expected composition of the fluid; and alabel generator responsive to the processor to generate a labelidentifying the fluid based on the comparison of the spectral data ofthe actual composition of the fluid with the spectral data of anexpected composition.
 2. The apparatus of claim 1, wherein the processoris adapted to determine the concentration of the fluid, and the labelgenerator is adapted to generate the label with an indication of thefluid concentration.
 3. The apparatus of claim 1, wherein the label is amachine readable label.
 4. The apparatus of claim 3, wherein the machinereadable label is an optically readable label.
 5. The apparatus of claim3, wherein the machine readable label includes an RFID component.
 6. Theapparatus of claim 1, wherein the fluid is contained within a containerhaving at least one wall through which the light is directed, theprocessor adjusting the spectral data of the actual composition of thefluid with spectral data representative of the wall prior to comparingof the spectral data of the actual composition of the fluid with thespectral data of an expected composition of the fluid.
 7. The apparatusof claim 6, wherein the spectral data representative of the wall isstored data determined by measuring spectral data of an empty container.8. The apparatus of claim 6, wherein the spectral data representative ofthe wall is determined by measuring spectral data of a wall of a fluidcontaining container in a non-fluid containing section of the container.9. The apparatus of claim 7, further comprising a data storage device,and wherein the data storage device is configured to store the expectedspectral data of the composition of a pre-formulated fluid.
 10. A methodof controlling delivery of a fluid, comprising: directing light throughthe fluid; sensing the light that was directed through the fluid afterthe light has passed through the fluid, and providing light sensorsignals representative of the spectral data of the actual composition ofthe fluid; comparing the spectral data of the actual composition of thefluid with spectral data of an expected composition of the fluid; andgenerating a label identifying the fluid based on the comparison of thespectral data of the actual composition of the fluid with the spectraldata of the expected composition of the fluid.
 11. The method of claim10, further comprising determining concentration of the fluid based onthe comparison of the spectral data of the actual composition of thefluid with the spectral data of the expected composition of the fluid.12. The method of claim 10, wherein the label is a machine readablelabel.
 13. The method of claim 12, wherein the machine-readable label isan optically readable label.
 14. The method of claim 12, wherein themachine-readable label includes an RFID component.
 15. The method ofclaim 10, wherein the fluid is contained within a container having atleast one wall through which the light is directed, and furthercomprising adjusting the spectral data of the actual composition of thefluid with spectral data representative of the wall prior to comparingof the spectral data of the actual composition of the fluid with thespectral data of an expected composition of the fluid.
 16. The method ofclaim 15, wherein the spectral data representative of the wall is storeddata determined by measuring spectral data of an empty container. 17.The method of claim 15, wherein the spectral data representative of thewall is determined by measuring spectral data of a wall of a fluidcontaining container in a non-fluid containing section of the container.18. The method of claim 10, further comprising: affixing the generatedlabel to a fluid container; reading the label at a delivery point;comparing the fluid identification on the label to an expected fluid atthe delivery point; preventing delivery of the fluid if the fluididentification on the label and the expected fluid at the delivery pointare inconsistent.
 19. The method of claim 18, wherein the delivery pointincludes a fluid pumping device, and a control device that controls thefluid pumping device, and further comprising inputting an identificationof the expected fluid to the control device, the control devicecomparing the fluid identification on the label to the inputidentification of the expected fluid and controlling the fluid pumpingdevice as a function of the comparing.
 20. The method of claim 19,wherein the control device controls the fluid pumping device to preventdelivery of the fluid if the fluid identification on the label and theexpected fluid at the delivery point are inconsistent, and to allowdelivery of the fluid if the fluid identification on the label and theexpected fluid at the delivery point are consistent.
 21. The method ofclaim 20, wherein the fluid pumping device is an infusion pump.
 22. Amethod of verifying a drug prior to delivery of the drug at a point ofcare, comprising the steps of: spectroscopically scanning a fluid;identifying a drug in the scanned fluid based on the scanning;generating a label indicating the drug based on the identifying of thedrug; and affixing the label to a fluid container containing the scannedfluid.
 23. The method of claim 22, further comprising: machine readingthe label of the fluid container at the point of care; comparing at thepoint of care the identified drug in the fluid container and indicatedon the label to an expected drug; and preventing delivery of the drug toa patient when the identified drug in the fluid container and indicatedon the label is inconsistent with the expected drug, and allowingdelivery of the drug to the patient when the identified drug in thefluid container and indicated on the label is consistent with theexpected drug.
 24. The method of claim 23, wherein the steps ofpreventing and allowing delivery includes controlling operation of apumping device.
 25. The method of claim 24, further comprising inputtingan identification of the expected drug into a control device.
 26. Themethod of claim 23, wherein the step of scanning the fluid includes:directing light through the fluid; and sensing the light that wasdirected through the fluid after the light has passed through the fluid,and providing light sensor signals representative of the spectral dataof the actual composition of the fluid.
 27. The method of claim 26,wherein the step of identifying a drug includes comparing the spectraldata of the actual composition of the fluid with spectral data of anexpected composition of the fluid.
 28. The method of claim 27, whereinthe step of generating a label includes identifying the fluid based onthe comparison of the spectral data of the actual composition of thefluid with the spectral data of the expected composition of the fluid.29. The method of claim 27, further comprising determining concentrationof the fluid based on the comparison of the spectral data of the actualcomposition of the fluid with the spectral data of the expectedcomposition of the fluid.
 30. The method of claim 27, wherein the fluidis contained within a container having at least one wall through whichthe light is directed, and further comprising adjusting the spectraldata of the actual composition of the fluid with spectral datarepresentative of the wall prior to comparing of the spectral data ofthe actual composition of the fluid with the spectral data of anexpected composition of the fluid.
 31. The method of claim 30, whereinthe spectral data representative of the wall is stored data determinedby measuring spectral data of an empty container.
 32. The method ofclaim 30, wherein the spectral data representative of the wall isdetermined by measuring spectral data of a wall of a fluid containingcontainer in a non-fluid containing section of the container.